 <div class="sidebar-box">
    <h4>Search</h4>     
    @using (Html.BeginForm("Results", "Search", FormMethod.Post, new { id = "frmsearch", @class = "searchform" }))
    {
        <input type="text" id="SearchText" name="SearchText" placeholder="type and hit enter" style="width:190px;" />
        <a href="#" id="submit-search" class="postfix button expand">Go</a>
    }
</div>
<script type="text/javascript">
    $(document).ready(function () {
        $("#submit-search").click(function (evt) {
            if ($("#SearchText").val().trim() != '')
                $("#frmsearch").submit();
            else
                alert("Please enter text to search");
            return false;
        });
    });
</script>